Physiology Flashcards
(104 cards)
1
Q
source of gastrin
A
G cells in antrum of stomach and duodenum
2
Q
source of somatostatin
A
D cells in pancreatic islets and gi mucosa
3
Q
source of CCK
A
I cells in duodenum and jejunum
4
Q
source of secretin
A
S cells in duodenum
5
Q
source of GIP
A
K cells in duodenum and jejunum
6
Q
source of motilin
A
small intestine
7
Q
source of VIP
A
para ganglia in sphincters, gall bladder and small intestine
8
Q
what cells found in duodenum and secreted what
A
G cells - gastrin I cells - CCK K cells - GIP S cell - secretion D cells - somatostatin
9
Q
what cells found in jejunum and secrete what
A
I cells - CCK
K cells - GIP
10
Q
function of gastrin
A
increased H secretion
growth of gastric mucosa
increased gastric motility
11
Q
stimulation of gastrin
A
stomach distension
alkalinisation
amino acids/peptides
vagus
12
Q
inhibition of gastrin
A
decreased pH < 1.5
13
Q
what causes gastrin to increased pathologically
A
h pylori chronic atrophic gastritis
Zollinger Ellison syndrome
chronic PPI use
14
Q
what are actions of somatostatin
A
decreased H secretion decreased pepsinogen secretion decreased pancreatic fluid secretion decreased intestinal fluid secretion decreased gall bladder contraction decreased insulin release decreased glucagon release
15
Q
what stimulats somatostatin
A
increased by acid
16
Q
what decreases somatostatin
A
decreased by vagus
17
Q
what is octreotide
A
somatostatin analogue
18
Q
treatment for acromegaly
A
octreodtide
19
Q
treatment for insulinoma
A
octreotide
20
Q
treatment for carcinoid syndrome
A
octreotide
21
Q
treatment for variceal bleeding
A
octreotide
22
Q
what does CCK do
A
increase pancreatic secrtion
increases gall baldder contraction
decreases gastric emptying
increases spincter of oddi relazation
23
Q
what stimulates CCK
A
fatty acids
amino acids
24
Q
how does CCk cause pancreatic secretion
A
acts on neural M pathways to increased pancreatic secretions
25
what does secretin do?
increases pancreatic HCO3 secretion
decreases gastric acid secretion
increases bile secretion
26
what stimulates secretin
acid
fatty acids in lumen
NO PROTEIN
27
why is the action of secretin important
neutralized acid from the stomach to permit action of pancreatic enzymes
28
what does GIP stand for?
flucose-dependent insulinotropic peptide
29
what does GIP do?
decrease H secretion
| increases insulin release - if oral, not IV
30
what stimulates GIP?
fatty acids
amino acids
oral glucose
31
what does motilin do?
produces migrating motor complexes
| MMC
32
what stimulates motilin
increases in fast
33
what is a motilin receptor angonist
erythromycin
34
what is a drug that can be used to stimulate intestinal peristalsis and why?
erythromycin bc tis a motilin receptor agonist
35
what does VIP do?
increases intestinal water and electrolyte secetion
increase relaxation of intestinal smooth muscle and sphincters
~*~think of clinical implications for VIPoma~*~
36
what stimulates VIP?
distension
| vagal
37
what inhibits VIP
adrenergic
38
copious watery diarrhea
hypokalemia
achlorhydria
VIPoma, non alpha, non beta islet cell tumor (VIP increases intestinal water and electrolyte secretion and realizes intestiona smooth muschle and spinhters.
39
what does NO do?
increased smooth muscle relaxation includint the LES
40
what pathology does the significance of NO relaxation of the LES exist in?
achalasia
| bird beak
41
what hormones cause H secretion
gastrin
ach
histamine
42
what hormones cause decreased H secretion
somatostatin
secretin
GIP
43
what hormones increased pancreatic secretion
CCk
secretin
GIP (insulin)
44
what hormones decrease pancreatic secretion
somatostatin
45
what hormones have an effect on smooth muscle?
gastrin - increases gastric motility
somatostatin - decreased gall bladder contraction
CCK - gall bladder contraction, decreased gastric emptying, increased sphincter of oddi relaxation, VIP - increased intestinal and water electrolye secretion and relaxation of intestinal smooth muscle and sphincters
NO: relaxation of spnihcters including LES
46
what hormones are stimulated by aa/protein?
gastrin
CCK
NOT SECRETIN
GIP
47
what hormones are stimulated by fatty acids
CCK
secretin
GIP
48
what hormeones are stimulated by oral glucose and not IV glucose
GIP
49
what hormones are stimulated by distension
VIP
| gastrin
50
what hormones are stimulated by vagus
gastrin
| VIP
51
where are parietal cells located
body/fundus of stmach
52
what do parietal cells make?
HCL and intrinsic factor
53
what causes parietal cell destruction
chronic gastriris
| pernicious anemia
54
what stimulates gastric acid production
stimulated by histamine, ach and gasrin
55
what inhibits gastric acid prodcution
somatostatin
GIP
PG
secretin
56
what is a gastrinoma
gastrin secreting tumor that causes high levels of acid and ulcers refractor to medical therapy (like PPI)
57
where does pepsinogen come from
chief cells in the body
58
where does pepsin come from
pepsinogen in an acid environment
59
what stimulates pepsinogen relase
vafal stimulation
| local acid
60
where does HCO3 come from
mucosal cells @ fundus of stomach, duodenum, salivary galnds, pancreas and brunner glands in the duodeunm
61
what stimulats HCO3 secretion?
increased when pancreatic and biliary secretinos increased
| secretin
62
how does gastrin exert effects on parietal cells
mostly indirectly through stimulation of ECL to produce histamine
also directly on pariental cells
ENDOCRINE
63
list the receptors on parietal cells
```
M3 receptor
CCKb
H2 receptor
SST receptor
PG receptor
```
64
list the receptors that are Gi
PG receptor
| SST receptor
65
list the receptors that are Gs
h2 receptor
66
list the receptors that are Gq
CCKb
| M3 receptor
67
what cause the alkaline tide
water and carbon dioxide form bicarb and hydrogen inside parietal cells. h is extruded from cell via HKATPase and HCOe goes to blood in exchange for CL that also leaves into the lumen to combine with H to fomr HCl.
68
what else can act on the pg receptor
misoprostal - inhibits
69
where do proton pump inhibitors work
on the HKATPase that's shooting H out to stomach and K into cell.
70
describe pancreatic secretions
isotonic always
71
pancreatic secretions low flow
high Cl, normal Na (high), normal K (low)
72
pancreatic secretions high flow
high HCO3, normal Na (high), normal K (low)
73
what is role of alpha amylase
starch digestion
74
how is alpha amylase secreted
in active form
75
what are lipases for
fat digestion
76
what are proteases for
protein digestion
77
list the proteases
trypsin, chymotrypsin, elastase, carboxypeptidases
78
how are proteases secreted
as zymogens that are activated in the duodenum by trypsin
79
describe how tryspinosgen is crucial to protein digestion
gets activated by enterokinase/enteropeptidase a brush border enzyme of the duodenum and jejunum so it can become active trypsin to activate other zymogens/proteases
80
where do you find enterokinase/enteropeptidase
brush border of duodenum and jejunum
81
how are carbs absorbed?
as monosaccharides: glucose, galactose, fructose
82
describe how monosaccs are absorbed at apical membrane
SGLT-1: Na dependent for glucose and galactonse
| GLUT5: fructose, facilitated diffusion - cannot be absorbed vrs a concentration gradient
83
how are monosaccs absorbed at basolateral membrane?
GLUT2 facilitated diffusion
84
how do you distinguish GI mucosal damage from other causes of malabsorption
D-Xylose absorption test
85
where is Fe absorbed
as Fe++ in the duodenum
86
where is folate absorbed
in the small bowel
87
where is B12 absorbed
terminal ileum with bile salts
| needs IF
88
describe histo and location of a peyers patch
unencapsulated lymphoid tissue in the lamina propria and submucosa of the ileum
89
what is an M cell?
specialized epi cells that sample and present antigens to immune cells
90
What happens when a moo is encountered in an M cell?
B cells are stimulated in germinal cenetres to differentiate into IgA secreting plasma celsl which ultimately reside in the lamina propria. Ig A gets protective secretory component and is transported across the epithelium to the gut to deal with the intraluminal antigen
91
what makes up bile
bile salts (primary conjugated with glycein or turaine - water soluble), phospholipids, cholesterol, bilirubin, water, ions
92
what is the rate limiting step in bile synthesis
cholesterol 7alpha hydroxylase
93
who cares about bile
everyone
94
why do we care about bile
digestion and absorption of lipids and fat soluble vits ADEK
cholesterol excretion
anti moo via membrane disruption
95
what is bodys only way to get rid of cholesterol
bile (what about people without a gallbladder!! give them bile acids and watch their cholesterol and atherosclerosis!?)
96
how does bile protect vrs moos?
membrane disruptionq
97
list the steps in bilirubin form heme to poop and pee :)
@ RES: heme - hemeoxygenase - biliveridin - reductase - bilirubin
@ blood: unconjugated bilirubin - albumin
@ liver: OATP passive transport of unconjugated bilirubin -- UDP glucoronosyl-transferase - conjugated bilirubin -- MRP2 active transport
@ gut bacteria: conjugate bilirubin -- urobilinogen
@ feces: stercobilin brown
@ circulation : urobilinogen 90% of 20% back to lvier and 10% of 20% to urobilin and urine
98
which bilirubin is water soluble
direct/conjucated
| CONSENANTS
99
which bilirubin is water insoluble
insoluble - vowels
| indirect/uncongucated
100
vitamin D deficicency
rickets: bone pain and deformity
osteomalacia: bone pain and muscle weakness
hypocalcemia tetany
supplement breast milk
101
vitamin E deficiency
hemolytic anemia, acanthocytosis
muscle weakness
posterior colomn and spinocerebellar tract demyelination
102
vitamin A deficiency
```
night blindness - nyctalopia
dry, scaly skin - xerosis cutis
corneal degeneration - keratomalacia
bitot spots on conjunctiva
immunosuppression
```
103
vitamin K deficiency
neonatal hemorrhage with increased PT and aPTT and normal bleeding time
give injection at birth - not in breast milk
104
what vitamin deficiencies can cause anemia
vitamin E - hemolytic
B12 - megaloblastic macrocytic anemia
B9 - megaloblastic macrocytic anemia
B6 - sideroblastic anemia due to impaired hemoglobin synthesis and iron excess.
